What you can do is set your Mylar Folder Monitor to monitor your completed torrent downloads. It will then post-process them from your completed torrent folder as if you were doing a manual post-processing. There is an option within the Advanced tab of the configuration that you can enable if you want to receive notifications when post-processing torrent downloads (meaning that the torrent was snatched by Mylar).

A future commit will allow the option to move/copy/symlink the torrents so if there was a desire to continue seeding, they could.